1. Field of the Invention
The present invention relates to a vacuum pump for producing low or high vacuum and including a housing having a gas inlet and a gas outlet, a pumping system located in the housing, a motor for driving the pumping system, and a control electronics for controlling operation of the pump and likewise located in the housing.
2. Description of the Prior Art
A design of vacuum pumps for producing low and high vacuum, which is conventional in state of the art, is described in European Publication EP-A 1 591 663 with reference to an oil-tight vane rotary vacuum pump. The pump, which is described in the European Publication has an asynchronous motor with a fan and control electronics located in a box secured to the motor. These components form together the pump drive and are flanged on the pump housing. The components, which are necessary for producing the vacuum, are located in the pump housing. In case of a vane rotary vacuum pump, the pumping system includes shaft, rotor, stator, and vane or vanes and is surrounded by an oil bath located in the pump housing. A large amount of heat is generated in the housing of a vacuum pump. The cooling is effected only by the fan, which is supported on the motor shaft and is located at an end of the vacuum pump remote from the pumping system. The drawback of this arrangement consists that it makes for a complicated heat balance.
Another drawback of this concept becomes apparent when the entire line of the vacuum pumps is considered. The line includes many models that differs from each other by their suction capacity and their end pressure. As a result, the drive of a pump includes different component, and different components are mounted on the pump housing or in its interior. This noticeably increases the production costs.
An object of the present invention is to provide a vacuum pump that would have an improved heat balance at reduced manufacturing and exploitation costs.